It has been demonstrated that cryogenic fluids may be used on-board aircraft as a fuel source. For example, some aircraft engines, such as the Tu-155 made by Tupolev, were configured to use natural gas as fuel. The natural gas may be stored on-board the aircraft as liquid natural gas (LNG), which is a cryogenic fluid. LNG can be stored on-board aircraft within a cryogenic tank that holds a volume of the LNG. A pump typically dispenses LNG from the internal volume of the cryogenic tank and supplies the LNG to the aircraft engine as natural gas via piping. But, as the level of LNG within the internal volume of the cryogenic tank decreases, the surface pressure exerted on the surface of the LNG may decrease. Such a decrease in pressure within the internal volume of the cryogenic tank may cause pressure variations downstream of the pump during operation of the aircraft engine. In other words, the pressure of natural gas supplied to the aircraft engine may vary over time, which may decrease the performance and/or disrupt operation of the aircraft engine. Moreover, decreasing pressure within the internal volume of the cryogenic tank may cause the pump to cavitate. For example, the decreasing pressure may reduce subcooling of LNG at the pump inlet. In addition or alternative to decreasing the reliability and/or increasing the cost of operating the pump, pump cavitation may decrease performance and/or disrupt operation of the pump.